The invention relates to a milling cutter, as well as a milling insert, used for chipforming and material removal operations. More specifically, the invention pertains to a milling cutter, as well as a milling insert, used for chipforming and material removal operations wherein there is enhanced delivery of coolant adjacent the interface between the milling insert and the workpiece (i.e., the insert-chip interface) to diminish excessive heat at the insert-chip interface.
In a chipforming and material removal operation (e.g., a milling operation), heat is generated at the interface between the cutting insert and the location where the chip is removed from the workpiece (i.e., the insert-chip interface). It is well-known that excessive heat at the insert-chip interface can negatively impact upon (i.e., reduce or shorten) the useful tool life of the milling insert. As can be appreciated, a shorter useful tool life increases operating costs and decreases overall production efficiency. Hence, there are readily apparent advantages connected with decreasing the heat at the insert-chip interface.
In this regard, U.S. Pat. No. 6,053,669 to Lagerberg discusses the importance of reducing the heat at the insert-chip interface. More specifically, Lagerberg mentions that when the cutting insert is made from cemented carbide reaches a certain temperature, its resistance to plastic deformation decreases. A decrease in plastic deformation resistance increases the risk for breakage of the cutting insert. U.S. Pat. No. 5,775,854 to Wertheim points out that a rise in the working temperature leads to a decrease in hardness of the cutting insert with a consequent increase in wear of the cutting insert. Each one of the Lagerbeg patent and the Wertheim patent discuss the importance of delivering coolant to the insert-chip interface.
Other patent documents disclose various ways to or systems for delivering coolant to the insert-chip interface. In this regard, U.S. Pat. No. 6,045,300 to Antoun discloses using high pressure and high volume delivery of coolant to address heat at the insert-chip interface. U.S. Patent Application Publication No. 2003/00820118 to Kreamer discloses grooves between the cutting insert and a top plate. Coolants flows through the grooves to address the heat at the insert-chip interface. U.S. Pat. No. 5,901,623 to Hong discloses a coolant delivery system for applying liquid nitrogen to the insert-chip interface.
It is readily apparent that in a chipforming and material removal operation, higher operating temperatures at the insert-chip interface can have a detrimental impact on the useful tool life through premature breakage and/or excessive wear. It therefore would be highly desirable to provide a cutter assembly (e.g., a milling cutter assembly), as well as a cutting insert (e.g., a milling insert), used for chipforming and material removal operations wherein there is an improved delivery of coolant to the interface between the milling insert and the workpiece (i.e., the insert-chip interface, which is the location on the workpiece where the chip is generated).
In a milling operation, the chip generated from the workpiece can sometimes stick (e.g., through welding) to the surface of the cutting insert (e.g., a milling insert). The build up of chip material on the cutting insert in this fashion is an undesirable occurrence that can negatively impact upon the performance of the cutting insert, and hence, the overall material removal operation.
Thus, it would be highly desirable to provide a cutting assembly (e.g., a milling cutter assembly), as well as a cutting inert (e.g., a milling insert), used for chipforming and material removal operations wherein there is enhanced delivery of coolant to the insert-chip interface so as to result in enhanced lubrication at the insert-chip interface. The consequence of enhanced lubrication at the insert-chip interface is a decrease in the tendency of the chip to stick to the cutting insert.
In a cutting operation such as, for example, a milling operation, there can occur instances in which the chips do not exit the region of the insert-chip interface when the chip sticks to the cutting insert. When a chip does not exit the region of the insert-chip interface, there is the potential that a chip can be re-cut. It is undesirable for the milling insert to re-cut a chip already removed from the workpiece. A flow of coolant to the insert-chip interface will facilitate the evacuation of chips from the insert-chip interface thereby minimizing the potential that a chip will be re-cut.
Hence, it would be highly desirable to provide a cutting assembly (e.g., a milling cutter assembly), as well as a cutting inert (e.g., a milling insert), used for chipforming and material removal operations wherein there is enhanced delivery of coolant to the insert-chip interface so as to reduce the potential that a chip will be re-cut. The consequence of enhanced flow of coolant to the insert-chip interface is better evacuation of chips from the vicinity of the interface with a consequent reduction in the potential to re-cut a chip.